Formulation and Evaluation of Poly-herbal Topical Cream for Hyperpigmentation

Abstract

Background: Hyperpigmentation occurs due to the overproduction of melanin. As free radicals promote melanogenesis, antioxidants are important to combat free radicals and normalize melanin production and inhibition of tyrosinase enzyme leads to inhibition of the biosynthesis of melanin. Considering these facts developing plant-based formulations to treat hyperpigmentation would be beneficial due to least adverse effects. Objectives: To formulate and evaluate a poly-herbal topical cream for hyperpigmentation by incorporating scientifically evaluated roots extract of Glycyrrhiza glabra, leaves and pods extract of Mimosa pudica for known antioxidant and tyrosinase inhibitory activities Methods: Initially, three different cold and vanishing cream bases from each were prepared and observed real-time and centrifugation stability for 14 days at 8°C, 28 ±5°C and 40°C temperatures to observe any instability mechanism. The dose of each plant extract was calculated based on the IC50 and LC50 values obtained for in-vitro biological assays and toxicology assays. Calculated doses were incorporated into stable cream bases and kept evaluating real-time and centrifugation stability for 90 days at the same temperatures at specified time intervals. The most physically stable polyherbal cream was evaluated for physicochemical properties by measuring viscosity, spreadability, pH, and homogeneity and observing organoleptic properties and cream type through microscope. Results: One cold cream base and all vanishing cream bases were stable throughout the 14 days at the mentioned temperatures. Phase separation was the main instability mechanism observed in unstable cold cream bases. The prepared poly-herbal cold cream was subjected to phase separation soon after the centrifugation. However, all poly-herbal vanishing creams were stable throughout the 90 days, and out of them, one vanishing cream was observed with better stability at three temperatures. It was obtained with 54700 cps viscosity, 6.1 gcms-1 spreadability, 6.5 pH. Further, it was an Oil-in-Water type homogeneous vanishing cream with a yellowish-white color and smooth texture along with a pleasant odor. Conclusion: It is concluded that the most stable poly-herbal vanishing cream will be recommended for further studies including pre-clinical and clinical trials before commercialization.